There is a variable valve mechanism 90 of a first conventional example shown in FIGS. 9 and 10 among the variable valve mechanisms. This variable valve mechanism 90 includes a central main arm 97 that contacts a central low lift cam 92 and that drives valves when swinging, a left sub arm 98 that contacts a left medium lift cam 93, and a right sub arm 99 that contacts a right high lift cam 94. A low lift state where the main arm 97 swings according to the cam profile of the low lift cam 92 is achieved by coupling neither the left sub arm 98 nor the right sub arm 99 to the central main arm 97. A medium lift state where the main arm 97 swings according to the cam profile of the medium lift cam 93 is achieved by coupling only the left sub arm 98 to the central main arm 97. A high lift state where the main arm 97 swings according to the cam profile of the high lift cam 94 is achieved by coupling both the left and right sub arms 98, 99 to the central main arm 97.